Device for tuning pianos.



N0- 806,949. PATENTED DEC. 12, 1905. G. BRAUN.

DEVICE FOR TUNING PIANOS.

APPLICATION FILED MAR-27, 1905.

I22 718M502 2 a 5 71 35 ZZZ/Q8366 r of jaw Wm mww H UW CARL BRAUN, OF ZURICH, SWVITZERLAND.

DEVICE FOR TUNING PIANOS.

Specification of Letters Patent.

Patented Dec. 12, 1905.

Application filed March 2'7, 1905. Serial No. 252,410.

To all whom it may concern.-

Be it known that I, CARL BRAUN, a citizen of Germany, residing at Zurich, Switzerland, have invented new and useful Improvements in Devices for Tuning Pianos, of which the following is a specification.

My invention relates to improvements in devices for tuning pianos; and the object is to provide means whereby the strings will remain at the required tension and thereby the piano in tune much longer than hitherto has been the case. I attain these objects by the device illustrated in the accompanying drawings, in which Figure 1 is an elevation and Fig. 2 a section thereof on line A B viewed from the left of a tuning device constructed in accord ance with one embodiment of my invention, while Fig. 3 is a detail of a modification thereofv Similar letters refer to similar parts throughout the several views.

Referring to Figs. 1 and 2, a bar a is secured upon the wrest-plank for each set of unison-strings. This bar has projections c with holes d. In front of each of these projections the bar a has a double ear 6, to which is hinged, by means of a pivot an arm g. Each arm g has a hole ac, widening toward the respective projection c. The opposite side of each of the said arms has an arc-like re cess h. The free end of each of the said arms has a screw-threaded hole i, in which is located the wrest-pin 7c, secured in position by a set-screw Z. One side of each of the said arms is provided with a rounded shoulder m, over which the string passes. Through the holes ac and d in the arm g and projection 0, respectively, passes a bolt 0 parallel to the sounding-board, having a square head and engaging in a cylindrical nut 19, located in the arm-recess h. The strings are, as usually, secured at one end to the string-plate, but near the other end placed over the rounded shoulder m over the top edge of the arm g, wound onto the wrest-pin 7c in the usual way and by turning the latter tensioned. The bolt 0 is then turned, which causes the arm g to move toward the respective projection c, and thereby tune the string to the proper pitch.

According to a modification of my invention, Fig. 3, I may form the pinhole i in the arm 9 at an incline instead of radial to the fulcrum thereof and taper as well as the shank of the wrest-pin, a set-screw Z being also provided to retain the latter in position.

In the tuning device described the wrestpin is not directly subjected to the strain of the tensioned string, but such is taken up in the first place by the rounded shoulder m, adjacent to the pivotf of the arm g, and is thus jointly borne by the said shoulder and wrestpin. The strain individually upon these parts is thus reduced, which causes the strings to remain in tune much longer than otherwise would be the case. Furthermore the double ears 6 and projections c of each set of unison-strings being upon one bar, the ap plication of the tuning device to the wrestplank can be affected more quickly than is the case in other tuning devices.

What I claim as my invention, and desire to secure by Letters Patent, is

In a device for tuning pianos, a bar, arms in number corresponding with that of the strings of one note fulcrumed thereto, awrest pin in each free end, and a tensioning-bolt through each of the said arms, the said bar being adapted to be secured to the wrestplank, each of the said arms having at the side between the fulcrum and wrest-pin, a rounded shoulder over which and the edge of the said arm the string passes to the said wrest-pin and projections on the said bar each carrying one of the said bolts, all combined substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CARL BRAUN.

witnesses CARL LANDWEHRLUE, A. LIEBERKNECHT. 

